JP2002176693A - Loud speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loud speaker having high efficiency that is applied to various video audio devices in which the occurrence of a defective magnetic gap can be small. SOLUTION: In the loud speaker having a narrow width of this invention, a voice coil 20 is constituted by inserting a coil part 20c between two sheets 20d, 20e, and the two sheets 20d, 20e are coupled. Thus, the deformation of the coil part 20c inserted between the sheets 20d, 20e will not be produced, defective magnetic gaps can be suppressed, the size of the magnetic gaps can be set to be narrower, independently of the deformation of the coil part 20c, then the highly efficient loud speaker can be realized also.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker used in various audiovisual equipment, and more particularly to a loudspeaker having a narrow width.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 6 is a cross-sectional view of a conventional narrow-width type so-called slim speaker in the short-diameter direction, FIG. 7 is a perspective view of a voice coil as the main part, and FIG.

According to FIG. 1, reference numerals 1a and 1b denote rectangular parallelepiped magnets which are magnetized in opposite directions. The upper plate 2 having an upper magnetic gap 2a is bonded and bonded, and the lower magnetic gap 3a is provided. The lower plate 3 is adhesively bonded to form a magnetic circuit 5.

Reference numeral 6 denotes a frame adhesively bonded to the upper plate 2. Reference numeral 7 denotes a vibration plate whose outer peripheral edge is adhesively bonded to the frame 6, and reference numeral 8 denotes a center of a short diameter of the vibration plate 7 in a long diameter direction. The upper part 8a is inserted through the formed slit 7a.
The voice coil is a planar voice coil whose lower part 8b is supported by a damper 10 which is bonded and fixed to the lower plate 3 via a damper supporting part 10a.

The voice coil 8 of the damper 10
, The upper and lower coil portions 8c of the voice coil 8 are formed by the slit-shaped magnetic gap 2a of the upper plate 2 and the slit-shaped magnetic gap 3 of the lower plate 3.
It is arranged so that each may be located in a.

[0006]

However, in the above-mentioned conventional speaker, since the coil portion 8c of the voice coil 8 is formed by bonding, the coil portion 8c is easily deformed.
When driven as a speaker, the coil portion 8c may contact the upper and lower plates 2 and 3 in the magnetic gaps 2a and 3a, respectively, due to the vertical driving of the voice coil 8, which may cause a gap failure such as generation of abnormal sound. Voice coil 8
And the assembly of the speaker were complicated.

In order to prevent this, the magnetic gaps 2a and 3a having a large interval have a problem that the magnetic flux density is reduced and the efficiency is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide an excellent speaker which can be easily assembled.

[0009]

According to a first aspect of the present invention, there is provided a loudspeaker using a planar voice coil.
Since the coil portion is sandwiched between the two sheets and the two sheets are joined to each other, the coil portion is sandwiched between the sheets so that the coil portion is not deformed and the magnetic gap defect is suppressed. At the same time, the size of the magnetic gap can be set narrow without assuming the deformation of the coil portion, so that the efficiency as a speaker can be improved.

According to a second aspect of the present invention, there is provided a speaker according to the first aspect, wherein the thickness of at least one of the contact portions of the two sheets sandwiching the coil portion of the voice coil is in contact with the coil portions. The thickness of the voice coil in the magnetic gap portion is reduced to further improve the efficiency as a speaker.

According to a third aspect of the present invention, there is provided a speaker according to the first aspect, wherein a reinforcing piece is provided integrally with the voice coil at least inside or outside the coil portion of the voice coil. Thus, the deformation of the voice coil is suppressed, the width of the magnetic gap is reduced, and the efficiency as a speaker is further improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a speaker according to the present invention will be described below with reference to FIGS. In the description, the same parts as those in the related art are denoted by the same reference numerals, and the description will be omitted.

(Embodiment 1) FIG. 1 is a sectional view of a slim speaker as a preferred embodiment of the present invention in a short diameter direction, and FIG. 2 is a perspective view of a voice coil which is an essential part of the speaker. FIG. 3 is a cross-sectional view of a planar voice coil which is the main part, and mainly describes the embodiments according to claims 1 and 2. FIG.

According to the drawing, the difference from the prior art lies in the planar voice coil, and the voice coil 20 is supported by the damper 10 and the upper portion 20a which is bonded to the diaphragm 7 in the same manner as the conventional one. A lower portion 20b is provided, and the voice coil 20 is connected to a coil portion 20c, a seat 20d,
20e.

That is, the coil portion 20c is sandwiched between the sheets 20d and 20e to be integrated. In the integration, the coil portion 20c is sandwiched between the epoxy resin sheets 20d and 20e mixed with mica or glass fiber. Then, heating and pressurization are performed to integrate the components. The heat resistance is improved by mixing mica or glass fiber.

In the voice coil 20 formed as described above, the coil portion 20c is covered with the sheets 20d and 20e, and the thickness is uniformly regulated by the mold used at the time of heating and pressing at the time of integration. The magnetic gap failure due to the deformation of the portion 20c can be prevented. Also,
Since the thickness is regulated by the mold used at the time of the above-mentioned heating and pressing, the setting of the magnetic gaps 2a and 3a does not need to consider the deformation of the coil portion 20c as in the related art.
The narrower setting can be performed more accurately, and the efficiency of the speaker can be improved.

Depending on the heating and pressing conditions, a flat voice coil 20 having a slight swelling in the coil portion 20c can be obtained. To improve the accuracy of the thickness of the voice coil 20 more, By forming a contact portion of at least one of the sheets 20d and 20e with the coil portion 20c in advance to be thinner than the other portion, the voice coil 20 with further improved flatness can be obtained, and the magnetic gap 2 can be improved.
This makes it possible to narrow the widths of a and 3a, thereby improving the efficiency of the speaker.

(Embodiment 2) Another embodiment of the speaker of the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view of a slim speaker in a short diameter direction, and FIG. 5 is a perspective view of a voice coil which is a main part of the speaker.
An embodiment according to the present invention will be described.

Referring to FIG. 1, reference numeral 21 denotes an upper portion 21a which is adhesively connected to the diaphragm 7, a lower portion 21b which is connected and supported to the damper 10, and a reinforcing piece 21d is formed inside the coil portion 21c. . The reinforcing piece 21d is provided between the two sheets as in the first embodiment.
When the voice coil 2 is inserted, the voice coil 2
1, the increase in man-hours during production of the voice coil 21 can be minimized, and the thickness of the magnetic gap 2a, 3a can be narrowed by controlling the thickness simultaneously with the coil portion 21c during heating and pressing. And
Since the deformation such as warpage of the planar voice coil 21 is suppressed by the reinforcing piece 21d, the magnetic gap 2 is further increased.
The widths of a and 3a can be reduced, and the efficiency of the speaker can be improved.

In this embodiment, the reinforcing piece 21d is provided inside the coil portion 21c. However, the reinforcing piece 21d may be provided outside, or both inside and outside. Can be provided as appropriate.

Further, the contact portion of the sheet sandwiching the reinforcing piece 21d is previously set to be thin to improve the planarity of the voice coil 21 in the same manner as in the first embodiment, thereby further reducing the width of the magnetic gaps 2a and 3a. It is also possible to provide a speaker with improved efficiency.

[0022]

As described above, according to the present invention, since the coil portion is sandwiched between the sheets, there is no deformation, the magnetic gap failure is suppressed, and the size of the magnetic gap is based on the deformation of the coil portion. Since it can be set narrow without any problem, the efficiency as a speaker can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a slim speaker according to an embodiment of the present invention, taken along a minor axis.

FIG. 2 is a perspective view of a voice coil which is a main part of the same.

FIG. 3 is a cross-sectional view of a planar voice coil which is a main part of the same.

FIG. 4 is a cross-sectional view of a slim speaker according to another embodiment of the present invention in a short diameter direction.

FIG. 5 is a perspective view of a voice coil which is a main part of the same.

FIG. 6 is a cross-sectional view of a conventional narrow-width slim speaker in a short diameter direction.

FIG. 7 is a perspective view of a voice coil as the main part.

FIG. 8 is a sectional side view of the same.

[Explanation of symbols]

 2a, 3a Magnetic gap 5 Magnetic circuit 6 Frame 10 Damper 20, 21 Voice coil 20c, 21c Coil section 20d, 20e Sheet 21d Reinforcement piece

Continued on the front page (72) Inventor Tomoyasu Takase 1006 Kazuma Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. 5D012 BA06 CA05 EA06 GA01

Claims (3)

[Claims] 1. A magnetic circuit having a slit-shaped magnetic gap, a frame coupled to the magnetic circuit, a diaphragm having an outer peripheral edge coupled to the frame, and a magnetic plate coupled to the diaphragm and coupled to the magnetic plate. A speaker comprising a planar voice coil inserted into a magnetic gap of a circuit and supported by a damper coupled to the magnetic circuit, wherein the voice coil has a coil portion sandwiched between at least two sheets. A speaker that combines two sheets. 2. The loudspeaker according to claim 1, wherein at least one of the planar voice coils has a reduced thickness at a contact portion of the two sheets sandwiching the coil portions with the coil portions. 3. The speaker according to claim 1, wherein the planar voice coil has a reinforcing piece provided integrally with the voice coil at least inside or outside the coil portion.